CRISPR and Sickle Cell Disease Flashcards
Define CRISPR
CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats.
CRISPR was initially discovered in prokaryotic cells, as a defense mechanism known as the CRISPR array, but is now also used as a genetic editing tool.
Outline the process of CRISPR including the Cas9 protein enzyme, guide RNA and template DNA (Prokaryotic cells)
In prokaryotic cells, CRISPR is used as a defense mechanism against attacking viruses. When a virus injects viral DNA into a cell, the bacteria capture the DNA and codes it into its own DNA. This is known as the CRISPR array. When the virus re-infects the same bacterial cell, the bacteria can ‘remember,’ the code for the virus. This allows a Cas9 enzyme complex containing guide RNA to track the targeted DNA and then cut said target DNA to destroy the viral infection.
Outline the process of CRISPR including the Cas9 protein enzyme, guide RNA and template DNA (Eukaryotic cell)
In eukaryotic cells, CRISPR is used as a tool to modify genes. The genome editing tools are entered into the cell and custom sgRNA designed by a scientist. The sgRNA which acts to guide the Cas9 protein, which is also a lab-designed complex created by the lab, is introduced to the cell through lab methods. This sgRNA then acts as a complementary side for the sgRNA to replace the targeted DNA.
Define the CRISPR Cas9 enzyme:
A bacterial RNA-guided endonuclease enzyme which can unwind DNA and break hydrogen bonds between the base pairs complementary to the guide RNA
Define the Guide RNA
A single-stranded sequence of RNA that attaches to the Cas9 enzyme which then finds the target DNA sequence in a gene , allowing the Cas9 to attach and ‘cut’ the DNA
Discuss evolving technologies CRISPR can be used for
CRISPR can be used for editing crops, embryo editing and gene drives
There are arguments for and against the use of technologies for CRISPR
